Sheet metal bending tool



y 1950 T. F. PAULS SHEET METAL BENDING TOOL Original Filed June 11, 1954m8 N N mm r MP M F. m w Tw United States. o r

2,938,413 SHEET rmra BENDING TOOL,

Original application Jane 11, 1954, Serial No. 436,021,. now Patent No.2,835,025, dated May 20, 1958. Di-

vided and this application Dec. :16, 1957, Ser..No. 706,534

1 Claim. (CI. 81-15) This invention relates to the manufacture of sheetmetal articles and more particularly to the manufacture of hollowarticles from sheet metal by fluid pressure inflation. 7

Therefore, it is an object -ofthis invention to provide an apparatus forforming an inlet opening at the edge-of the hollow sheet.

The invention will be better understood in connection with a descriptionof a specific embodiment together with an accompanying drawing in which:

Figure l is a side elevational view partially in cross section showingthe angular relationship of the shears and the metal plate for adaptingthe plate for opening by one embodiment of the tool of this invention;

Figure 2 is a side elevational view also partly in cross section showinga succeeding stage of the cutting operation;

Figure 3 is a fragmentary perspective view showing the structure of thecut produced by the shears;

Figure 4 is an elevational view showing one tool suitable for operatingon the edge structure to accomplish opening, with the metal plate shownin the cross section at the opening; and

Figure 5 is a perspective view of another embodiment of the opening toolof this invention.

For purposes of illustration, the tool of this invention will bedescribed by reference to its application to forming an opening in aninternally laminated sheet obtained by the method described in US.Patent No. 2,690,002. As illustrated in the drawings, an embryonicsystem of passageways, within the metal sheet, is provided by aconnecting laminar portion extending from the system of passageways toan edge of the sheet. In order to facilitate this sheet for expansion,the edge, to which the connecting laminar portion extends, is cut orsheared to provide a beveled edge on which the tool of this inventionmay operate.

More specifically by reference to Figures 1, 2 and 3 of the drawing,such a sheet metal plate 1 of annealed aluminum having an includedlaminar pattern of internally disposed system of embryonic passages orinternal laminations is provided with a beveled edge by being positionedbetween open shear blades 3 and 4 so that an extension 2 of the patternis disposed at the bight of the shear. It is advantageous to select insome cases a sheet metal plate 1 having a dual pattern the extension 2of each of which is common to both. It is apparent that with such anarrangement cutting of sheet metal plate 1 at the extension 2 at theaxis of pattern symmetry provides two units with only one cut 15 each ofwhich will be suitable for further operation in accordance with thisinvention which will become apparent hereinafter.

The front faces 5 and 6 of shear blades 3 and 4 respectively are out ofline sufficiently to provide the usual clearance necessary forsatisfactory operation of the shearing mechanism. Leading face 7 ofblade 3 is swept back as shown in Figures 1 and 2 so that the cuttingedge of leading face 7 passes and crosses the cutting edge of Figure -3.

2,938,413 Patented .May 31, 1960 leading face 8 of blade 4 withobliquity at the usual angle, generally about 5. The sheet metal plate 1is disposed in the bight-of' the shear in such a manner that the platemakes an anglewith the cutting plane of the.

shear to provide a'beveled edge such as illustrated. in

The beveled sheet metal edge -structure specifically shown in Figure3 isobtained'in accordance with the teachings of the parent co-pendingapplication Serial No. 436,021 filed June 11, 1954, now U.S. Patent No.2,835,025. This beveled edge is characterized by a sloping edge which asa general rule in made up of the smoothly sheared or burnished portion14 and the fractured portion 18 across both of which the front face 5 ofshear blade 3 passed. Indentation 16 is merely the mark left bythe'leading face 8 of the other shear blade 4. At

about the line of demarcation between portions 14 and 18' of the slopingcut a line 17 of the inlet extension 12 is very ostensibly exposed. Thisline 17 is thus not only very readily located with the unaided eye butis adaptable for application by the opening device of this inventionwith no difliculty.

As can be readily seen in Figure 3, line 17 defines a potential openingto the embryonic system of passageways between the metal sheet and isdefined by a protuberant lip portion 21 formed from the protruding metalsheet component at the beveled edge and by the receding lip portion 22formed from the receding component sheet at the beveled edge to adaptthe sheet to operation by the tool of this invention.

In order to accomplish opening of the inlet extension 12 at the line ofexposure 17, an opener such as shown in Figure 4 may be applied toproduce the opening 20. The tool consists of a body portion 23 having astepped portion or shoulder 24 spaced from a bearing surface 25 by a gap26 the width of which is equal to one-half the thickness of sheet metalunit 10. For example, the width of gap 26 is about 0.031 of an inch whenthe gage of unit 10 is 0.062 of an inch. Tool body 23 is provided withthe pivot point 27 about which body 23 together with its shoulder 24 maybe turned so that shoulder 24 bears against the protuberant lip 21thereby prying lip 21 away from receding lip 22 to form the opening 20.

Tool body 23 of the opener also carries means for forming an entrance atinlet extension 12. The meansshown takes the form of a drift punch 28the front end of which is pointed at 29 to facilitate entry of the punchinto the initial opening 20.

"Figure 5 illustrates the above opening tool as a separate hand operateddevice which comprises a tool holder 31, such as a rigid rod and thelike, having mounted on its rear portion a dimensional transition member32. This transition member 32 may be of any convenient configuration,such as the conical form illustrated, to provide a gradual transitionfrom the holder 31 to the handle or grip 35 mounted on the rear end ofmember 32. Handle 35 is preferably, as illustrated, knurled at portions34 to provide an additional gripping aid when the tool is hand operated.

Mounted on the front end of rod 31 is an opener 23 reciprocating theprotuberant lip 21 from the receding lip 22 of the sheet unit 10. Asabove, the opening tool has a stepped or shoulder portion 24 spaced froma hearing surface 25 by a slot or gap 26. The dimension of slot 26 issubstantially equal to the difference between the thickness of the sheetmetal unit and the thickness of the receding lip 22. This dimensionenables the slot to receive therein the protuberant lip 21 and tothereby enable applying a force on the protuberant lip 21 through the2,938,418 A v 1 f edge of the shoulder'portion 24 upon pivoting 'it'about a. fulcrum resulting from the action of the edge 21,. oi. 7

bearing surface 25, against the sheet metal unit at a point, inwardly ofthe beveled edge. Upon pivoting or rotating; thQlIGQEBZEGDt theextendedledges '21; hearing; against the sheet metalfum't; the.shouldeinportionzfi bends the'protuherant v lip 21 'hythe applied forcethereon, to pry it'away firomiuthe reeeding 'lip fil. a; 2:1"

' Since,- may other; embodiments act this invention may: occur to thoseskilled in the art, it is to be understood: the foregoing is; intended:by way. of illustration of a preferred embodiment and nohas alimitation; of the scope: of the-present invention except-v as:,set:.forth in the ap-J- pended claim. h a I v This applicationis a divisionoffco-pending applicationi Serial. Ncs 436,021 filed June: 1711, 1954;new U'.S. Patent. No. 2,835,925.; Y

What I ciaimxasmy. inventionis;

A. hand tool for effecting; an. opening. between a pair of superposedmetal sheets; having sealedtogethenedge portions, and forminga sheetmetal unit; said unit having. beveled edges at one end thereof; and; aslit opening into the interior thereof through the heveledend' portion;oneof the metal sheetsprotrudingbeyondtheother sheet at the beveled endof the unit; said hand tool comprising raitoolihody providedwithaslotfor the reception of the lip portion of the protruding. metal sheet andwith a fulcrum projection in extension of the bottom of the slot, saidslot defining a gap of a dimension substantially equal to the difierencebetween the thickness of the sheet metal unit and the thickness ofithe'other of said sheets; said fulcrum projection constituting-pivot, meanson one side 1 of the gapytlie forvvardedge of the upper wall of said 10slot constiutingha; bending m'eansffori engaging the pro trudin'g lip'p'ortioh;saidforwardiedge'.having'a width not in excess oi the width \ofsaid sheet for applying a force. t'oithe sheet'aboutisaid fulcruni, i'na direction away from the-other sheetgandk substantially'normal to theplane of 15 the sheet" unit, andhan dl'e means for manipulating the toolbody.

References Cited in the file of this patent UNITEDISTATES PATENTSGrenell- Aug. 5, 195 8'

